“A vigorous market of consumer preferences is exercised at the grocery-cart level. Some decisions include menu planning, buying generic brands, buying bulk or larger quantities for lower unit cost, specific sales from weekly ad scrutiny, shopping in multiple stores including big box stores, finding substitutes, purchasing inferior goods, or just saying no to pricey or discretionary items. Searching for more reasonable prices increases the time and mobility necessary to find bargains, adding opportunity costs to the equation.

The nominal cost of goods measured is more punishing to the consumer when we add these efforts to economize. They are paying more with weaker dollars after exerting an effort to pay less for their real cost of goods, even if they could exercise shopping discretion.”

https://mises.org/wire/ruling-classes-are-inflation-deniers-and-ship-fools-sails